This article explores the current state of the creation and use of evidence by managers for cost containment in hospitals. We assert that hospitals do not know enough about what things cost, and until they get evidence on costs, it is not likely that much can be done to narrow the chasm between common practice and best practice. Part of the problem is that managers do not seek out available evidence that exists, and part of the problem is a lack of sufficient research efforts to generate evidence for managers to use. The article strives to help direct future efforts by researchers and managers in the area of evidence-based cost containment research by presenting a framework for priorities that managers and researchers can use to increase the amount of research done to generate evidence and to increase the use of evidence by health care managers.